Deductive LogicTopic #8 of 10

Truth Tables

Using tables to determine the validity of propositional logic statements.

A truth table is a mathematical table used in logic to compute the functional values of logical expressions on each of their functional arguments.

Symbols

  • Negation (¬\neg or ~): Not P
  • Conjunction (\land or &): P and Q
  • Disjunction (\lor or v): P or Q
  • Implication (\rightarrow): If P then Q
  • Biconditional (\leftrightarrow): P if and only if Q

Basic Tables

Conjunction (AND)

True only if both premises are true.

PQP \land Q
TTT
TFF
FTF
FFF

Disjunction (OR)

True if at least one premise is true.

PQP \lor Q
TTT
TFT
FTT
FFF

Implication (Conditional)

False only if P is True and Q is False.

PQP \rightarrow Q
TTT
TFF
FTT
FFT